This invention relates to apparatus for measuring two dimensions of an object and combining the measured values to obtain a single value. In particular embodiment, this invention relates to a device which can be used to measure the inside diameter and height of internal combustion engine air filters having the configuration of a hollow cylinder, and which device automatically combines the two measurements to obtain a single value that is read off a reference frame, the value comprising the model number of a replacement air filter.
At the present time, when it becomes necessary to replace the air filter of an automobile internal combustion engine, one must consult a manufacturer's catalogue which identifies the correct replacement filter for each model of vehicle and engine displacement. For the inexperienced employee, and even for the experienced, this is a time consuming method and errors frequently occur. When the apparatus of this invention is used, the correct replacement filter can be accurately determined in a matter of seconds cutting down significantly on customer waiting time.
The principle of this invention may also be used to construct a device that will measure two dimensions of other types of objects which can be uniquely identified by combining such dimensions to obtain a single value.